1. Field of the Invention:
This invention relates to a suspension, and more particularly to a suspension for a vehicle provided with a shock absorber capable of adjusting a damping force and having a control shaft disposed in a piston rod for adjusting the damping force.
2. Description of the Prior Art:
When a piston rod of a shock absorber is connected to a car body, an assembly is employed which interposes a rubber bushing between the piston rod and the car body to prevent vibrations from being transmitting from the shock absorber to the car body. This applies also to the case of a shock absorber capable of adjusting a damping force.
With few exceptions (for example, Japanese Utility Model Public Disclosure (KOKAI) No. 76837/83), the bushing cannot change its spring constant after being incorporated in the car body with a predetermined shape or the like since the spring constant is determined unconditionally.
U.S. patent application Ser. No. 753,785 concerns a construction in which a shock absorber having a piston rod is connected to a car body. In this assembly, a bushing disposed radially outward of a valve base connected to the piston rod has a plurality of fluid chambers which are adapted to communicate to and be insulated from each other by a valve body disposed on the valve base. However, the damping force of the shock absorber cannot be adjusted.